Designed for the 1976 Olympic Games, Olympic Stadium was not completed on time due to a strike by construction workers. The (556-foot-high) leaning tower used to retract the roof stood half finished until 1987 when the roof was finally completed. It took another 2 years before the roof, made from 60,696 square feet of Kevlar weighing 50 tons, became retractable.

The Stadium was remodeled in 1991, with 12,000 seats being removed for Expos games. In September of that year, one of the stadium's 55-ton concrete beams fell, forcing the Expos to play a handful of home games on the road. Problems with opening and closing the roof led to its permanent closure in 1992. The roof was removed in May of 1998, turning the park into an outdoor stadium for the season. In the spring of 1998, the orange Kevlar roof was removed and a $26 million opaque blue roof replaced it later in the year. The new roof does not open. The stadium’s total cost has exceeded $1 billion.

The Expos played some of their home games during the 2003 and 2004 seasons at Hiram Bithorn Stadium in San Juan, Puerto Rico. The team announced they were moving to Washington, DC on September 29, 2004. A move had been in the works since the team was bought by the other 29 Major League Baseball team owners in 2002.

Trivia:

All messages were in French and English.

When the Expos played an American team, the Canadian and American national anthems were sung before each game.

Spectators could ride the metro (subway) to the ballpark via the Pie IX and Viau metro stations.

Hosted the 1982 All-Star game.

The tower is one foot taller than the Washington Monument and is angled at 45 degrees. It is the world's tallest inclined structure.

The observation deck at the top of the tower can be reached by a 2-minute ride in a 90-passenger cable car.

The retractable roof was silver on top and orange on the bottom with 26 white cones that linked the roof to the tower. Retracted like a large umbrella, it took 25 minutes to hoist the roof up or down on its 26 cables and could not be deployed when the wind was greater than 25 miles per hour.

The roof improved offense by keeping out extreme cold.

The distance from the field to the apex of the roof is 171 feet.

An orange line was painted on the technical ring, which surrounded the stadium on the inside of the roof, after Dave Kingman hit it with a controversial foul ball. After that, Darryl Strawberrry and Henry Rodriguez hit the technical ring with balls that were ruled fair, and therefore home runs, because of the orange line.